The invention relates to a method for cleaning industrial pipe systems, more precisely to a method for cleaning industrial pipe systems, preferably pipe systems used in food industry, such as meat, fish and vegetable industry, where detergent and liquid are fed into a pipe to be cleaned, and a pressure difference is created in the pipe and the detergent and liquid are brought to flow in the pipe by means of a pressure difference in order to clean the pipe.
In food industry the pipes transferring foodstuffs have to be cleaned in due time for hygienic reasons in order not to contaminate the foodstuffs transferred therein. A conventional way to clean these pipes is to feed water and detergent through the pipes. The cleaning process also includes cleaning with a disinfectant and rinsing. For example in dairy industry the cleaning agent is often fed in from one end of the pipe to be cleaned using pumps, in which case the flow is maintained until the cleaning agent flows out from the other end of the pipe. The required power of the pump has to be high, since the length of the pipe can extend up to hundreds of meters and the flow rate is, for example, 2-4 m/s. As the diameter of the pump is large, considerable amounts of cleaning agent and disinfectant have to be fed. Owing to the above, cleaning a pipe becomes very expensive.
The cleaning agent, disinfectant and rinsing agent (typically water) can be brought to flow using negative pressure as an alternative for using a pump, which is the conventional means for causing the flows. This is known from slaughtering lines. However, known systems utilizing negative pressure have not been able to provide a desired and an adequate cleaning result.
Known apparatuses for cleaning industrial pipe systems are arranged to transfer, depending on the work phase, washing agent, disinfectant or rinsing agent into the pipe along the entire length of the pipe. The water amounts used are generally large and the actual cleaning phase includes several feedings of the substances, as the inner surface of the pipe is rarely adequately cleaned during one treatment. On account of the above, known apparatuses do not enable the pipe systems to be cleaned rapidly and inexpensively.
It is an object of the invention to provide a method removing said drawbacks.
In order to achieve this the present invention provides a method for cleaning industrial pipe systems, having pipe walls, by mechanically treating the walls thereof, said method comprising
feeding a detergent together with liquid and granules, having a diameter, in batches only into of a pipe of the pipe system to be cleaned, the pipe having a cross-section, whereby one wash batch has a volume in liters, which is 0.05-0.3 times the numerical value of the cross-section in square centimeters of the pipe;
creating a negative pressure in the pipe; and
bringing the wash batch to flow in the pipe by means of the negative pressure for cleaning and mechanically treating the walls of the pipe.
Preferred embodiments of the method of the invention are disclosed below.
One of the greatest advantages of the method of the invention is that it allows industrial pipe systems having a large diameter in particular to be cleaned considerably more economically and more appropriately than previously.